Chainsaw Repair
Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Stihl => Topic started by: middlefork on September 24, 2012, 09:18:56 am
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This Stihl was running rough and then would die . I changed spark plug , gas filter , air vent , then took carb apart and changed diaphram, metering diaphram and both gaskets . Still having same trouble . It is hard to start then runs rough when it does start and it will not stay running . I took the carb apart again and there is gas in carb , so it is getting the gas up to it . thanks
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Make sure needle lever is set correctly and gaskets and diaphgrams are in the right order. Fuel line, intake boot, impulse line, crank seals are other things to check. 028 is older saw if it were mine and I was keeping it I'd replace them.
Shep
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The 028 is the baby brother of the 038,042 and 048 models just smaller .Due to it's age it would not be a surprise if the impulse hose has deteriated . Often times a leaking impulse hose will give the same symptons as a stiff main diaphragm .It just does not expand the diaphragm enough to supply enough fuel .I had the same deal on an 048 which is probabley why the thing ended up on flea bay to begin with .
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Is the impulse hose the one that the carb slides into ??? thanks for the help
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Yep lower right hand side looking at the carb .Goes from the carb to the crankcase .
Left hand side is the fuel .
You could have a little leak in the fuel hose too , it's got some age on it if it's the original .
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OK I took off the impulse line and it seems to be OK . I can put suction on it and it can hold the suction , but I can change the hose anyway. Maybe one less thing to deal with . Any other ideas . thanks
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When I first read OP post I thought of seals. Going through the other stuff is what I do too till I figure out seals is the only thing left it could be.
Keep us updated.
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I have taken off the Fuel line, intake boot, impulse line and they all look very good . All have good rubber and I can hold pressure in all three . So if they are good , whats next the crank seals ? I have never changed this before , can I do this myself ??
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Do you have a 028 IPL or service manual? I havent been that far into a 028 aka seals.
I havent even checked to see if the IPL and work shop manual is on my CD either.
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I have no manuals , I have just owned this saw for about 2 years . I looked on utube and they have a video of changing the seals . The flywheel side doesn't look too bad,...... but the clutch side looks a lot harder . Not sure if I want to tackle that .
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Could I have condenser problem ? I put everything back together and it fired up and ran for about 3 seconds then would not start or fire again .
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Have you checked to see if you have spark &/or fuel at the plug?
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If it's got points it's an early model .They list three different ignition systems for that saw . The points type Bosc plus a solid state Bosc and a solid state SEM coil .
If it's got points it might not be a bad idea to burnish the points and reset them .I'm guessing at around 18 thou opening but I'd have to check to be certain .
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I checked and I have plenty of spark , the spark plug is firing on every pull . I tried to start it and it would run rough for a while but would never smooth out . After a while while running rough it would die .
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I don't mean to sound like a smart azz but once I had the spacer gasket out of order on a Stihl 042 and it about drove me nuts .Made me so mad I banished the thing to the shelf for a year and half to punish it .
Now I know I had that carb apart at least a half dozen times and it never dawned on me and Lawd only knows how many carbs I've rebuilt .
I could get it fired up but the pot licker did just about what you are experiancing ,run a short and die on the vine .
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I just took off the carb and cleaned every port , put all the gasket and diaphrams back in according to the diagram I got from the Stihl dealer . Put it back together and same thing . I don't know what else to do at this point .
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On the check valve side of the carb no matter if it's an Hu Tillotson or A (I think ) Walbro Wt carb there is a teeny weenie little screen .That thing is the last line of defense to stop stuff in the gasoline from entering the carb .
Fact the screen is so fine it will catch stuff that can pass through the fuel filter .If it gets clogged no amount of tugging on the string will get it started .It can be such a thing as it becoming clogged but appears clear . You about have to pluck it out with a needle and look at it .
It can be blown out with compressed air but hang onto it with a pair of needle nose pliers because if it gets away you'll never find it again .
I'm not saying that's it but I've been down that road before .Fact blown a screen into orbit myself a time or two ,then dig through my junk until I find another .
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Yeah that is the first thing I cleaned last week . thanks
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Still will not run .
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When you are trying to start it does the plug get wet or stay dry? Pull it through hard a 8 or 10 times with the choke on & then check. Assume it feels like it's still got good compression?
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When you are trying to start it does the plug get wet or stay dry? Pull it through hard a 8 or 10 times with the choke on & then check. Assume it feels like it's still got good compression?
On a difficult start, I always make this evaluation. I think this is very important.
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It has very good compression . After 10 pulls the plug smelled of gas but I couldn't see a lot of gas on it . After checking this , I put it back in and it would fire and try to start but would never run .
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It obviously is not getting fuel for some reason which goes right back to fuel delivery .You either have a plugged fuel line ,no impulse or a screwed up carb .If that thing has fire and fuel it's got to at least fart a time or two even if it won't putt .